The present invention relates to a ball mill for the continuous very fine grinding and dispersing of solids in a liquid.
Ball mills are known having a housing, the inner face of which defines a grinding chamber in which a displacement body is mounted. The liquid and solids together with grinding balls are loaded into the grinding chamber and are rolled by the relative rotation of the displacement body and housing, the result of which is to grind the solids and mixture with the liquid. Usually the grinding chamber has the form of a cylinder and the displacement body is a cylindrical or conical rotor. Even if the gap between the surface of the housing and the rotor varies as by mounting the rotor eccentrically, the effect on the material to be ground is unsuitable for many purposes, the more so as the path of the movement of the material in the housing is relatively short.
In German patent specification DE-PS No. 814,374, there is shown a ball mill for making varnishes having an upwardly enlarged conical housing, into which there is inserted a similarly conical displacement body. The gap between housing and displacement body provides room, however, for only one layer of balls, which individually apply against both the grinding surfaces of the housing and of the displacement body simultaneously, resulting invariably in an insufficient grinding effect.
It is the object of the present invention to provide, combined with limited dimensions of the ball mill, the greatest possible variety of grinding action on the material to be ground, so as to obtain as thorough and as uniform as possible a fine grinding and dispersing of the solids in the liquid.